Author's Note: This is very short at the moment, 'cause the muse isn't being particularly helpful, but if you like it then please review and tell me what I can do better!
Note: Set in Season 3, after Gridlock.
Once she had gotten used to the idea of Rose's ghost being a semi-permanent feature of her new life – and with a man as obsessed by her as The Doctor appeared to be, that didn't take long – Martha found herself finding it easier to know when it was a good idea to engage The Doctor in conversation about what they had done that day, and when it was better to fade into the background by going to her room or trying to properly "get her bearings" in the TARDIS (a place she still wasn't completely sure wasn't partly alive itself).
At first, she'd tried to use his mood as some form of barometer. That failed when she realised that Time Lord moods did not always correlate with their human "equivalents" or, indeed, bear any relation to human ones whatsoever. She could recall, even now, the positive dismay with which she digested the fact that the 'happy, bouncy' Doctor was actually more likely to be depressed – or whatever the alien equivalent was in that planet of his. What was its name, again? Oh, yes. Gallifrey.